Silicon最新文献

Silicon carbide (SiC) power devices exhibit significant potential in ultra-high voltage (UHV) power electronics applications due to their ability to simplify circuit topology and enhance energy conversion efficiency. The increasing demand for higher breakdown voltages has led to greater termination lengths and more complex structures. Therefore, termination technology has become a critical challenge in UHV SiC power devices. This paper discusses three crucial issues involved in UHV SiC termination technology, namely avalanche model, analytical method, and structure configuration. First, a comparative analysis of avalanche breakdown models is performed to elucidate the physical characteristics of SiC impact ionization coefficients. The identified model parameters provide a theoretical basis for predicting the breakdown voltage of SiC termination. Furthermore, two innovative models are proposed to facilitate the efficient design of termination configuration and reduce the complexity of structure traversal calculation in UHV termination: a multi-ring iterative model based on voltage superposition and a sector depletion model based on charge balance. Finally, the technical features of state-of-the-art UHV SiC terminations are analyzed to gain insight into the electric field modulation principles of various structure configurations. The design considerations are also discussed with a focus on the feasibility of different termination categories in UHV devices.

Single-crystal silicon, a widely used substrate material for Micro-Electro-Mechanical Systems (MEMS), has been extensively studied for its quasi-static mechanical properties. However, data concerning its mechanical properties at high strain rates are scarce, and corresponding research is insufficient, thereby severely limiting the extended applications of silicon-based MEMS. This study first conducted three sets of high strain rate tests on single-crystal silicon using a Split Hopkinson pressure bar (SHPB) system to successfully acquire its dynamic stress–strain curves. Subsequently, the experimental results were utilized to calibrate and validate the finite element simulations performed in ABAQUS, ensuring the accuracy of the numerical modeling. Finally, a machine learning model based on a Backpropagation Neural Network (BPNN) was developed. This model utilizes the incident wave parameters from SHPB experiments as input features to predict the mechanical properties of single-crystal silicon at high strain rates. The results indicate that the developed BPNN-based machine learning prediction model exhibits excellent applicability. It can effectively circumvent the extensive and time-consuming processes of finite element simulation modeling, analysis, and post-processing. Furthermore, it accurately predicts the mechanical properties of single-crystal silicon at high strain rates and demonstrates the potential to extrapolate stress–strain curves to even higher strain rates. This research provides a valuable reference for subsequent work on establishing strain rate-dependent constitutive models for single-crystal silicon, optimizing the design of silicon-based MEMS structures, and expanding the applications of silicon-based MEMS.

This study presents a novel analytical and numerical framework for exploring the coupled photothermal, elastic, and plasma wave interactions in semiconductor materials under the GNII model, providing explicit solutions that capture the complex interplay of thermal, elastic, and carrier dynamics without energy dissipation. Specifically, the model addresses the interaction of thermo-elastic waves with plasma effects when subjected to high-intensity laser irradiation. The analytical solutions for these complex phenomena were derived using an eigenvalue approach combined with Laplace transform methods, providing explicit and precise formulations in transformed domains. Numerical inversion of these analytical solutions enabled detailed observation and analysis within the time domain. Comprehensive numerical computations were conducted using silicon-like semiconductor media to validate the model and explore the interplay among thermal, elastic, and plasma responses under varying laser intensities. The distribution of field quantities is significantly impacted by the photo-generated carrier lifetime and pulse rise time, which is a significant phenomenon, according to the graphical data.

This review critically synthesizes recent advances in rare-earth element (REE) doped bioactive glasses (BAGs), focusing specifically on how Lanthanum (La), Dysprosium (Dy), Terbium (Tb), Holmium (Ho), Gadolinium (Gd), and Yttrium (Y) alter glass structure and thereby mechanical performance and biomedical function. Unlike previous reviews that emphasize either bioactivity or optical/magnetic properties alone, our manuscript integrates atomic-scale structural evidence, processing-dependent effects (melt-quench vs sol–gel), and in-vitro/in-vivo outcomes to link dopant chemistry with osteogenesis, antimicrobial activity, imaging functionality and mechanical reliability. We also discuss practical challenges for scale-up, safety and clinical translation, and propose targeted future research directions. This integrated perspective aims to guide design decisions for next-generation BAG scaffolds and implant coatings where combined mechanical robustness and therapeutic functionality are required.

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This paper investigates the influence of silicon dopant concentration on the performance of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). AlGaN-based DUV-LEDs are critical for applications like sterilization and water purification but face efficiency challenges due to carrier imbalance and material defects. The study focuses on optimizing the hole-blocking layer (HBL) doped with silicon (Si), as HBL design significantly impacts carrier mobility, carrier confinement, and radiative recombination. Using MATLAB's one-dimensional drift–diffusion charge control (1D-DDCC) software, the research examines dopant concentrations ranging from 1 × 10¹⁵ cm⁻³ to 1 × 10²⁰ cm⁻³ in six different devices with three quantum wells. Simulations will analyse carrier density, current density, energy band diagrams, radiative recombination rate, electric field, current-voltage (IV) characteristic, quantum efficiencies, and luminescence to determine the optimal doping level that minimizes defects while maximizing efficiency. Expected outcomes include identifying a doping range that balances recombination rate and quantum efficiency, leading to enhanced DUV-LED efficiency and stability. These findings aim to advance sustainable ultraviolet technologies and set a benchmark for future semiconductor designs.

During vertical channel 3D NAND fabrication, plasma-induced damage creates surface defects, which lead to the formation of voids at different locations of the subsequently grown epi-plug. The void's location, especially near the edge of the substrate-epi plug, as well as in the side wall of the epi-plug, is more critical. The void at the edge of the substrate-epi plug increases V_th, SS, and R_ch and reduces I_on, compared to no void. Voids along the sidewall of the epi-plug also significantly affect electrical performance. Further trap formation around the void degrades performance, increasing V_th, SS, and R_ch while significantly reducing I_on compared to without trap. Traps around voids far from the GSL (Ground Select Line) similarly degrade performance as those near the GSL and epi-plug edge. We also investigated the effects of voids during program/erase characteristics. Our study emphasizes how the geometric location of voids and the distribution of surrounding traps influence the reliability and electrical performance of 3D NAND devices.

This study investigates the structural and optical properties of zinc oxide (ZnO) thin films deposited on porous silicon (PSi) substrates using three different fabrication techniques: radio frequency (RF) sputtering, sol–gel spin coating, and thermal evaporation. Characterization was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and photoluminescence (PL) spectroscopy. All ZnO/PSi samples exhibited high-quality polycrystalline films with low defect densities. Among the methods used, the RF sputtering technique achieved the best electrochemical performance. The maximum current density (Jmax) and Michaelis–Menten constant (K_M) were found to be 570 μA and 680 μM (0.68 mM), respectively, demonstrating efficient enzyme immobilisation on the ZnO/PSi electrode surface and a strong affinity between the immobilised glucose (GOx) molecules and glucose molecules. Furthermore, the glucose biosensor demonstrated moderate sensitivity over the linear detection range (500 μM to 2000 μM), with a linear range slope (LRS) of 40 μA/cm²/μM, and a correlation coefficient (R²) of 0.9543.

This research examines the effects of hot water conditioning on mechanical, thermal conductivity, flammability, and water absorption behaviour of the epoxy based composites. Nanofibers was extracted from mango peel using the retting process, while jack fruit peel powder was utilized as filler materials. Both the fiber and filler were chemically treated using 3-Aminopropyltrimethoxysilane (silane coupling agent) to enhance the composites performance. The hot water conditioning was conducted at 50 °C for 15 days. The overall performance of the composites was noticeably affected by conditioning, with the hot water conditioned composites exhibiting slightly reduced mechanical values compared to the unaged ones. Among them, composite SP2 (containing 2 vol.% filler) had the maximum tensile strength (150 MPa), flexural strength (156 MPa), and impact strength (5.8 J). Conversely, the unconditioned composite containing 4 vol. % filler (SP3) exhibited the highest thermal conductivity (0.391 W/mK) and surface hardness value of 87 Shore-D.Hot water conditioned composite (SP6) showed the highest water absorption (6.2%) and the slowest flame propagation speed (7.86 mm/min). The failure mechanisms and surface morphology of the composites were analysed using scanning electron microscopy (SEM).These epoxy-based composites, reinforced with agro-waste fibers and fillers, with their improved mechanical, thermal, and flame-retardant properties, are suitable for applications in lightweight structural components, interior panels, thermal insulation, water-resistant construction materials, and other eco-friendly consumer goods.

The escalating demand for sustainable construction materials has intensified the exploration of alternative binders to Portland cement aimed at reducing energy consumption and CO₂ emissions. Concurrently, the disposal of toughened glass waste (TGW) in landfills poses a growing environmental challenge. This study investigates the synergistic pozzolanic potential of toughened glass waste powder (TGWP) and fly ash (FA) in blended cement pastes, emphasizing their mechanical and microstructural evolution. Fly ash was incorporated to mitigate the high alkalinity of the cement matrix, thereby minimizing the chemical degradation of TGWP. Experimental evaluations encompassed flow characteristics, compressive strength, and advanced characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM). Results demonstrated that the rheological properties were strongly influenced by the particle morphology and fineness of the supplementary materials. The optimum blend containing 15% TGWP and 15% FA achieved a 16.81% increase in compressive strength after 90 days, attributed to the delayed pozzolanic reactivity of TGWP. XRD confirmed reduced calcium hydroxide and enhanced calcium silicate hydrate (C–S–H) formation, while FTIR evidenced intensified Si–O and Al–O bonding. FESEM coupled with EDS analysis revealed a densified microstructure and formation of calcium–alumino–silicate–hydrate (C–A–S–H) phases, affirming the pozzolanic activity of TGWP. The integration of TGWP and FA in cementitious systems represents a promising pathway toward eco-efficient binders, offering a dual advantage of waste valorisation and carbon footprint reduction in the construction sector.

Chlorination roasting is widely recognized as one of the most effective methods for removing lattice impurities. However, there are few studies on HCl gas chlorination roasting. To study the effect of HCl gas chlorination on the migration and removal of lattice impurities in quartz, the gangue minerals in quartz were first removed by the pre-purification process. The pre-purified quartz is subjected to HCl chlorination roasting in a wide high-temperature range of 900–1250 °C. The crystal structure changes of quartz and the mechanism of lattice impurity migration and removal were systematically studied by XRD, SEM, FTIR, TGA, XPS, and ICP-OES. The results show that after pre-purified quartz sand is roasted in HCl at 1200 °C for 2 h, high-purity quartz sand with a purity of 99.996% can be obtained. Chlorination roasting has a significant removal effect on the quartz lattice impurities Na and K, and a certain removal effect on impurities Al, but it has no impact on impurities Li and Ti. Chlorination roasting above 900 °C can effectively remove H₂O and -OH from quartz, causing lattice expansion, which is beneficial for the migration and removal of impurities. The changes in the chemical composition of the quartz surface provide evidence for the formation and volatilization of chlorides.